There are almost 19,000 different species of amphibians and reptiles.
From snakes to lizards and frogs to salamanders these animals are famous all around the world.
However, there are many differences between amphibians and reptiles. They are two distinct groups of different animals.
Frogs and salamanders are amphibians. Snakes, lizards, turtles, and tortoises are reptiles.
Have you ever wanted to know the difference between a lizard and a frog? Read on to learn about the major differences between amphibians vs reptiles.
Article Contents
What Is An Amphibian?
The word amphibian comes from the Greek word for “double life”.
Amphibians are animals that start life in an egg in water. They then hatch into aquatic larvae, which live in the water and swim. These larvae undergo metamorphosis to become adults and live on land. However, they will continue to spend some time in water.
All Amphibians are cold blooded animals and need bodies of water to live. Most of the time they breathe through gills as hatchlings. They also have sensitive skin to help them live in their moist environment.
They are much more sensitive to changing environments than reptiles. This is because of their sensitive skin. Climate change, pollution and habitat destruction has made them the most threatened group of animals on the planet.
There are over 6,800 species of amphibians and about 500 subfamilies or genera. These species include:
- Frogs
- Toads
- Salamanders
- Newts
- Caecilians
Frogs make up between 85% and 90% of all Amphibians. They are four-legged, short-bodied and tailless.
Salamanders are amphibians with four legs, but they are long-bodied and have long tails.
Caecilians are long, limbless amphibians that do not have tails. Not much is known about them due to their shy and secretive nature.
What Is A Reptile?
Reptiles are cold-blooded animals with dry, scaly skin.
Most have four legs, or are descended from four-legged animals (e.g. snakes). Though not traditionally classified together, reptiles are closely related to birds.
This group of animals lays eggs that are leathery in texture, though some give live birth, like humans.
Reptiles are born on land, and continue to live on land as adults. Some species prefer to live near water, but most will live on land and in trees.
These animals are ectothermic and cannot generate internal body heat. Therefore, they bask in direct sunlight and lay under warm objects to maintain a high internal body temperature. This is why it is common to see lizards in warm states like Florida. Many are specifically adapted to live in humid or arid environments.
There are more than 10,000 reptile species recorded. These species include:
- Lizards
- Snakes
- Turtles
- Crocodilians
- Tuataras
- Amphisbaenians
The class Reptilia is defined as a group of the most recent common ancestors of diapsids. Diapsids are any reptile with two temporal openings in the skull. It is a very old class dating back hundreds of millions of years.
Difference Between Amphibians And Reptiles
Amphibians and reptiles belong to different classes of animal.
Every amphibian belongs to the class Amphibia. This class consists of frogs, toads, salamanders, newts and caecilians. Reptiles belong to the class Reptilia. These are turtles, tortoises, crocodilians, lizards, snakes, and tuataras.
Amphibians are older than reptiles. They first appeared in the Late Devonian Period, 363 million years ago. Reptiles appeared in history in the Late Carboniferous Period, 315 million years ago.
When amphibians first appeared, they lived in swampy environments, while reptiles thrived in dryer habitats.
Amphibians have different tongues when compared to other animals. Their tongues are meant to be quick and sticky to catch prey. Many reptiles’ tongues are forked to smell their surroundings to the left and the right. They also snatch up prey with their mouths, not tongues.
Amphibian vs reptile skin is very different too. Amphibians have porous, sensitive skin meant for being underwater. This makes them very sensitive to dehydration and environmental skin injuries.
Meanwhile, reptile skin is covered with keratinous scales to protect them against harsher environments. Many scales can be bony, like on turtle shells and crocodilians. They outgrow their scales as they age and shed them.
Another difference when comparing an amphibian vs reptile is the way they breathe.
When amphibians hatch, most of the time they breathe through gills like a fish. They live in the water. It is not until they undergo metamorphosis that they often develop lungs and can go onto land.
Reptiles breathe with their lungs as soon as they hatch. If they go underwater, they must hold their breath to avoid drowning.
Finally, there is a large difference between the way reptiles vs amphibians lay their eggs.
Amphibians lay their eggs in the water, where the offspring will spend their larval stage. These eggs do not have a shell and are often clear. Reptile eggs have leathery shells and are often deposited in sand or soil. When it is ready to hatch, the reptile will use its egg tooth to break free.
| Reptiles | Amphibians | |
|---|---|---|
| Class | Reptilia | Amphibia |
| Species | 10,000 + | 6,800 |
| Animals | Turtles, tortoises, crocodilians, lizards, snakes, and tuataras | Frogs, toads, salamanders, newts and caecilians |
| Era | Late Carboniferous Period about 315 million years ago | Late Devonian Period 363 million years ago |
| Skin | Scaly, keratinous skin | Sensitive, porous skin |
| Tongue | Forked to smell their surroundings to the left and the right | Quick and sticky to catch prey |
| Defense | Can be venomous | Can be poisonous |
| Respiratory system | Breathes with lungs | Breathes through gills, then breathes through lungs and skin |
| Metamorphosis | No | Yes |
| Range | Can live in a wide range of habitats, including water, trees, and deserts | Always found near water |
| Eggs | Shelled eggs that are often in dirt or sand, not in water | Eggs without a shell that are in or near water |
1. Tongues
Amphibians, especially frogs, are known for their sticky tongues to catch buzzing flies.
Their tongues can grab nearly any surface and pull up to 1.4 times their body weight. The tongue is connected to the front of the lower jaw, which opens quickly and causes the tongue to project. Most can grab prey faster than a human can blink.
Amphibian tongues are unique because they can stick to an insect and also act like a bungee cord.
Most reptiles do not have a quick, sticky tongue that projects to catch prey. They are ambush hunters and will snatch food with their mouths. Some species are an exception, such as the chameleon, which has a long, quick tongue.
Though not all reptile tongues are the same, many of them are forked.
Reptiles use their tongues to smell their surroundings.
A forked tongue helps them determine which direction a scent may be coming from. Some species of snake like Ball Pythons also use infrared thermal radiation to detect movement. This is a feature that amphibians do not have.
2. Eyes
There are many shared characteristics between amphibian and reptile eyes.
Many amphibians spend a lot of their time in the water, so their eyes are positioned near the top of their head to peer above the water surface. Nearly all species have slit-shaped pupils that can be horizontal or vertical.
Reptile eyes are very similar. Crocodilians, geckos, and some snakes often have vertical slits for pupils.
Generally, nocturnal species will have vertical slits, while diurnal species will have rounded pupils.
3. Skin
Mammals have fur, birds have feathers, and amphibians have sensitive, porous skin. They do not have the hard scales that reptiles do.
Amphibians have porous, semi-permeable skin which means that they can breathe through their skin as water and oxygen can pass through it. However, this also makes them more sensitive to the environment and means they can never be found too far away from water.
Some amphibians can be poisonous because of their skin.
The skin of amphibians can secrete toxins that may be poisonous to humans or predators.
Unlike amphibians, reptile skin is not poisonous.
However, poisonous is often confused for venomous. Venom comes from a bite and spreads through the bloodstream, whereas poison may secrete from the skin and only affects other individuals when consumed.
When a reptile is venomous, it produces a toxin in its fangs that it can inject into a victim when it bites it. Many species of snake are venomous.
Reptiles have developed hard scales that are made of keratin, a protein that makes up hair and nails too. Scales are used to protect them from predators and prevent water loss. Scales do not grow with the reptile. They are shed with the skin as they grow.
4. Habitat
Amphibians start the first phase of their lives in water. They then spend the adult phase living on land, but spend most of their time in water.
They are very dependent on the moisture in their environment to stay healthy. They are influenced by the distribution and amount of water in an area, particularly how much rain there is. Because of this, they can be found in nearly any freshwater ecosystem in the world.
Some Amphibians will bury themselves deep in dry environments to reach moisture in the ground, though this is not common.
Reptiles do not rely on ponds and lakes as much as amphibians.
It is common to find reptiles in many different habitats around the world.
Most reptiles prefer hot environments, though there are many that are found in more temperate weather. Many turtles can be found in ponds and lakes all around the world. Snakes and lizards prefer hot, arid habitats.
Their skin allows them to tolerate more harsh environments than amphibians, such as deserts and other dry habitats.
No matter where they live, they need access to suitable basking areas and shelter.
5. Breathing
There is a difference between amphibians and reptiles in how they breath.
Amphibians are unique when it comes to breathing. Larvae are born in water and then undergo metamorphosis to spend their juvenile and adult stages on land. The larvae primarily breathe through gills, much like fish.
Many amphibian larvae will also swim towards the surface and “suck” bubbles. Bubble-sucking happens when the water does not have a high enough oxygen content for a tadpole to survive, so they take in air from near the surface.
As they go through metamorphosis, they can develop several different breathing techniques.
Some absorb oxygen through their semi-permeable skin, others use lungs and some use a combination of both.
Reptiles breathe through their lungs, just like birds and mammals. They have lungs and respiratory muscles that are controlled by spinal nerves. Their chest muscles move their lungs up and down to suck air in and pump it out.
Many species go through invariable breathing alternated with breath-holding, in which breath-holds are interrupted by a series of breaths.
6. Eggs
All amphibian species will deposit their eggs in or near bodies of water. Individuals that live in rapidly-moving water often lay sticky eggs or lay them under stone so that they are not swept away by the current.
Reptile eggs have leathery shells and are often deposited in sand or soil, not water.
The main difference between amphibian vs reptile eggs is the presence of a shell.
In egg-laying reptiles the egg includes the shell, albumen, yolk, and yolk sac. Their eggs are similar to a chicken egg. Amphibian eggs do not have shells, but rather jelly capsules that serve as the entry and exit way for oxygen.
Reptile eggs must exchange heat, gas, and water with the substrate or surrounding air too. The difference is their eggs cannot incubate when surrounded by a liquid, so must use a substrate.
Most amphibians have external breeding. This means that the eggs are fertilized outside of the female’s body, and these eggs are laid in water. Fertilization often occurs without direct mating between the male and the female.
7. History
Amphibians appeared in Earth’s timeline much earlier than reptiles did.
However, both groups have been around for millions of years. They have so many similarities that they were even classified together until the 1900s.
All modern species are part of the class Amphibia which includes species like frogs, toads, salamanders and newts. The class Amphibia first appeared in the Late Devonian Period 363 million years ago.
Some evolved to become the dominant land vertebrates in the Carboniferous Period about 300 million years ago. This period was characterized by swampy environments, allowing them to thrive.
The classification of reptiles is more complicated and convoluted.
They were first classified by their skull shape in the late 19th century by Albert Gunther, a zoologist and herpetologist. They were then further divided by their nasal anatomy in the late 1950s. Today, the class Reptilia include lizards, snakes, tuataras, crocodilians, dinosaurs, turtles and tortoises.
The classification of Reptilia is more unnatural than Amphibia because Crocodilians are more closely related to birds than other reptiles.
Most evidence of ancient reptiles starts with the Late Triassic Period about 230 million years ago.
Evidence of early amphibian ancestors is difficult to find. Most ancient lineages became extinct before the Jurassic Period 200 million years ago. This was when dinosaurs became more prominent in the food chain.
Common Misconceptions
Are Frogs Reptiles?
No. Frogs are not reptiles. They are actually amphibians and are from the class Amphibia. Frogs are often confused with reptiles because they can look similar to many lizards.
An adult frog will lay its eggs in water, and those eggs will hatch into larvae called tadpoles. Tadpoles breathe through their skin and “bubble-sucking” until they undergo metamorphosis. Their bodies get wider and they will start growing back legs. As the back legs grow, the front legs start to grow and the tail starts to shrink.
Eventually, the tadpole is considered to be an adult frog and spends time on land. An adult frog stays near the water for the rest of its life and will lay its eggs near or in the water.
Are Turtles Reptiles?
Turtles are often confused with amphibians because of the amount of time they spend in water, but turtles are reptiles.
Turtles hatch from leathery shells onshore. Turtles are born with their shells and lungs, and they must hold their breath underwater. They also have scaly skin and keratinous shells, unlike amphibians that have soft, sensitive skin.
Do Reptiles Have Gills?
No, reptiles do not have gills. Reptiles do not have a need for gills as they do not spend time underwater permanently. While turtles, and some snakes and lizards, know how to swim and are considered to be aquatic, they come to the surface for air
Some amphibians have gills in their larval stage to swim underwater.
Amphibian and Reptile Similarities
Reptiles and amphibians belong to different groups of animals, but the term for studying these two groups of animals is called herpetology. These two groups of animals first emerged hundreds of millions of years ago.
Amphibians and reptiles share so many similarities that they were classified together until the 1900s:
- Both are cold blooded and rely on external temperatures to maintain their high body temperature.
- They have similar anatomies, as they both have two eyes each, a mouth, nostrils, and an opening for waste, and a reproductive structure called a cloaca.
- They both lay eggs and start their lives by hatching.
- They share many habitats throughout the world. Both are found on every continent in the world except Antarctica, although only some reptiles live in the world’s oceans.
- Both can be found in freshwater. Amphibians rely on freshwater to live. Many reptiles live near ponds and lakes, especially turtles. Some amphibians can even live in drier environments by burying themselves to find moisture.
- Most amphibians and reptiles do not have similar tongues. However, some reptiles, like chameleons, have fast, sticky tongues like amphibians to catch prey.
- Their eyes are very similar to each other. Nearly all of them have slitted eyes, whether they are vertical or horizontal.
- Many amphibians and reptiles have four legs, disregarding snakes. In fact, all frogs, salamanders, lizards, turtles, and crocodilians walk on all fours.
Summary
There are many differences between amphibians and reptiles.
All amphibians need to live in or near water to survive. They spend the first part of their lives under the water, and then return to it when it is time to lay eggs. Meanwhile, reptiles lay their eggs on land.
Some reptiles spend most of their time in the water, like turtles and crocodilians. However, most prefer hot environments, whether they be humid or arid.
Reptiles live in more harsh environments. Because of this, they have scales to protect their skin. Amphibians have semi-permeable skin to be able to breathe.
Understanding the differences between reptiles vs amphibians is especially important in owning one. They have different husbandry needs due to their different biology.
Do you keep reptiles or amphibians? Let us know in the comments!
